Valve prosthesis for implantation in the body and a catheter for implanting such valve prosthesis

Abstract

A valve prosthesis for implantation in the body by use of a catheter includes a stent made from an expandable cylinder-shaped thread structure including several spaced apices. The elastically collapsible valve is mounted on the stent as the commissural points of the valve are secured to the projecting apices. The valve prosthesis can be compressed around balloons of the balloon catheter and inserted in a channel, for instance, in the aorta. When the valve prosthesis is placed correctly, the balloons are inflated to expand the stent and wedge it against the wall of the aorta. The balloons are provided with beads to ensure a steady fastening of the valve prosthesis on the balloons during insertion and expansion. The valve prosthesis and the balloon catheter make it possible to insert a cardiac valve prosthesis without a surgical operation involving opening the thoracic cavity.

What is claimed is: 
     
       1. A valve prosthesis for implantation in a body, comprising:
 an elastical stent comprising a cylindrical support having circumferentially expandable sections comprised of a series of loops with commissural supports therebetween and integral therewith; and 
 an elastical valve, commissural points of which are mounted on a respective one of the commissural supports; 
 wherein the cylindrical support is radially collapsible for implantation in the body via a catheter. 
 
     
     
       2. The valve prosthesis according to  claim 1  wherein:
 the elastical valve comprises a biologically tribolate valve. 
 
     
     
       3. The valve prosthesis according to  claim 1 , wherein:
 the elastical valve comprises a cardiac valve. 
 
     
     
       4. The valve prosthesis according to  claim 1 , wherein:
 the elastical valve comprises a venous valve. 
 
     
     
       5. The valve prosthesis according to  claim 1 , wherein:
 the cylindrical support comprises a metal having a stiffness sufficient to prevent a contraction of the cylindrical support of more than about 10% following expansion. 
 
     
     
       6. The valve prosthesis according to  claim 1 , wherein:
 the cylindrical support comprises a thread structure which forms a cylinder surface. 
 
     
     
       7. A valve prosthesis for implantation in a body, comprising:
 an elastical stent comprising a support means having circumferentially expandable sections comprised of a series of loops with commissural supports therebetween and integral therewith; and 
 an elastical valve, commissural points of which are mounted on a respective one of the commissural supports; 
 wherein the support means is radially collapsible for implantation in the body via a catheter and the support means extends axially for supporting the elastical valve. 
 
     
     
       8. The valve prosthesis according to  claim 7 , wherein:
 the support means is cylindrical. 
 
     
     
       9. The valve prosthesis according to  claim 7 , wherein:
 a surface of the support means is cylindrical. 
 
     
     
       10. The valve prosthesis according to  claim 7 , wherein:
 the elastical valve is a biologically trilobate valve. 
 
     
     
       11. The valve prosthesis according to  claim 7 , wherein:
 the support means is expandable upon removal from the catheter. 
 
     
     
       12. The valve prosthesis according to  claim 7 , wherein:
 the elastical valve comprises a cardiac valve. 
 
     
     
       13. The valve prosthesis according to  claim 7 , wherein:
 the elastical valve comprises a venous valve. 
 
     
     
       14. The valve prosthesis according to  claim 7 , wherein:
 the support means comprises a metal having a stiffness sufficient to prevent a contraction of the support means of more than about 10% following expansion. 
 
     
     
       15. A valve prosthesis for implantation in a body, comprising:
 an elastical stent comprising a cylindrical support having a thread structure cylinder surface; and 
 an elastical valve, commissural points of which are mounted on the cylinder surface; and 
 wherein the cylinder surface is radially collapsible for implantation in the body via a catheter, 
 the thread structure comprises stainless steel wire folded in a plurality of loops, bended according to a circle, and welded to provide at least two closed rings, 
 the at least two closed rings are mutually connected end to end to form the cylindrical support, and 
 three loops in an external one of the rings are folded with a greater height than remaining ones of loops to form apices. 
 
     
     
       16. The valve prosthesis according to  claim 15 , wherein:
 the cylindrical support is expandable upon removal from the catheter; 
 each of the closed rings comprises a wire having a diameter of 0.55 mm; 
 a height of the remaining ones of loops is approximately 8 mm; 
 a height of the three greater height loops is approximately 14 mm; and 
 the cylindrical support and the elastical valve mounted thereon, when collapsed, have an outer diameter of approximately 10 mm and, when expanded, an outer diameter of approximately 30 mm. 
 
     
     
       17. The valve prosthesis according to  claim 15 , wherein:
 the stent is made to be fixed, through expansion of the cylindrical support upon removal from the catheter, at one point in a channel in which the valve prosthesis is implanted, which point is different from a point where the elastical valve is mounted on the stent. 
 
     
     
       18. A valve prosthesis for implantation in a patient's body without requiring open heart surgery, comprising:
 a self expandable stent constructed to be radially compressible and re-expandable, the stent having a top end, a bottom end and a metallic outer surface configured to contact native tissue in a body channel; and 
 a collapsible and re-expandable elastical valve comprising three flaps formed entirely of biological tissue, the elastical valve positioned within an interior portion of the stent for folding and expanding together with the stent, the elastical valve located between the top and bottom ends of the stent, the elastical valve having three commissural points sutured to the self expandable stent, the elastical valve configured to allow blood to flow in one direction such that blood is capable of flowing through the stent from the bottom end toward the top end; 
 wherein the valve prosthesis is radially compressible from an expanded condition to a compressed condition, the compressed condition having a first outer diameter of 10 mm or less for insertion inside a tubular wall of a cap along a distal end portion of a delivery catheter for advancement through a small inlet opening into the body channel and wherein the valve prosthesis is radially self-expandable upon ejection from the cap to a re-expanded condition comprising a second outer diameter of approximately 27 mm or more such that the second outer diameter of the valve prosthesis is greater than an inner diameter of the body channel for securing the valve prosthesis in the body channel without suturing the valve prosthesis to native tissue and to establish valvular function in the body channel, thereby allowing implantation of the valve prosthesis in the body channel for replacing the function of a natural aortic valve in an adult human being without open heart surgery and wherein the valve prosthesis is detachable from the delivery catheter such that the delivery catheter can be removed from the body channel and the small inlet opening can be closed such that the patient can resume a substantially normal life. 
 
     
     
       19. The valve prosthesis according to  claim 18 , wherein:
 the self-expandable stent has a height comprising a first range configured to be positioned downstream of the coronary ostia and a second range configured to support the elastical valve between the coronary ostia and the left ventricle. 
 
     
     
       20. The valve prosthesis according to  claim 19 , wherein:
 the elastical valve is formed entirely of biological tissue from a pig heart. 
 
     
     
       21. The valve prosthesis according to  claim 18 , wherein:
 the elastical valve comprises a venous valve. 
 
     
     
       22. The valve prosthesis according to  claim 18 , wherein:
 the stent has a stiffness sufficient to prevent a contraction of more than about 10% following re-expansion. 
 
     
     
       23. The valve prosthesis according to  claim 18 , wherein:
 the stent comprises a grate shaped structure which forms a cylinder surface. 
 
     
     
       24. A valve prosthesis configured to be implanted in a body channel without open heart surgery for replacing the function of a natural aortic valve in an adult human being, comprising:
 a radially compressible and re-expandable metallic stent having a top end, a bottom end and a metallic outer surface configured to directly contact surrounding native tissue in a body channel with a pressure sufficient to prevent detachment from the body channel; and 
 a radially collapsible and re-expandable valve positioned within an interior portion of the stent and sutured to the stent for folding and expanding together with the stent, the valve having three flaps formed of biological tissue from a pig, the three flaps positioned between the top and bottom ends of the stent for allowing blood to flow in one direction such that blood is capable of flowing through the stent from the bottom end toward the top end, the valve having three commissural points sutured to the stent; 
 wherein the valve prosthesis is radially compressible from an expanded condition to a compressed condition, the compressed condition having an outer diameter of less than 12.5 mm to be located inside a tubular wall of a cap along a distal end portion of a catheter for advancement through a small inlet opening into the body channel and wherein the valve prosthesis is radially re-expandable upon ejection from the cap to a re-expanded condition comprising an outer diameter of approximately 27 mm or larger for securing the valve prosthesis to the surrounding native tissue without suturing the valve prosthesis to the surrounding native tissue and wherein the valve prosthesis is detachable from the catheter such that the catheter can be removed from the body channel and the small inlet opening can be closed and wherein the metallic stent has a sufficient height such that the top end of the stent is capable of being positioned downstream of the coronary ostia while the valve is positioned substantially between coronary ostia and a left ventricle of a heart for replacing the function of the natural aortic valve without open heart surgery. 
 
     
     
       25. The valve prosthesis according to  claim 24 , wherein:
 at least a portion of the metallic stent is substantially cylindrical. 
 
     
     
       26. The valve prosthesis according to  claim 24 , wherein:
 the metallic stent is self-expandable upon ejection from the cap and wherein the outer diameter in the re-expanded condition is slightly larger than an inner diameter of the body channel. 
 
     
     
       27. The valve prosthesis according to  claim 24 , wherein:
 the radially collapsible and re-expandable valve comprises a cardiac valve. 
 
     
     
       28. The valve prosthesis according to  claim 24 , wherein:
 the radially collapsible and re-expandable valve comprises a venous valve. 
 
     
     
       29. The valve prosthesis according to  claim 24 , wherein:
 the metallic stent comprises a grate shaped structure having a stiffness sufficient to prevent a contraction of the metallic stent of more than about 10% following re-expansion. 
 
     
     
       30. A valve prosthesis for replacing the function of a native valve in a patient's body by a technique of catheterization, comprising:
 a radially collapsible and re-expandable stent having a top end, a bottom end and a metallic outer surface configured to contact native tissue in a body channel; and 
 a collapsible and re-expandable valve structure positioned within an interior portion of the stent and sutured to the stent, the valve structure having three flaps formed entirely of biological tissue, the three flaps positioned between the top and bottom ends of the stent, the valve structure having three commissural points sutured to the stent, the valve structure configured to allow blood to flow in one direction such that blood enters through a bottom opening at the bottom end of the stent and exits through a top opening at the top end of the stent; 
 wherein the valve prosthesis is radially collapsible to an outer diameter of less than 10 mm for introduction by way of a catheter through an inlet opening into the body channel and wherein the outer diameter of the stent is radially re-expandable to a re-expanded dimension sized to engage the native tissue in the body channel with a pressure sufficient for preventing detachment from the body channel and for fixing the valve prosthesis in the body channel without suturing the valve prosthesis to native tissue and wherein the valve prosthesis is detachable from the catheter such that the catheter can be removed from the patient's body and the inlet opening can be closed while the valve prosthesis remains in the body channel; 
 wherein the valve structure has an expanded outer diameter in the range of about 25 to 27 mm. 
 
     
     
       31. A valve prosthesis for replacing the function of a native valve in a patient's body by a technique of catheterization, comprising:
 a radially collapsible and re-expandable stent having a top end, a bottom end and a metallic outer surface configured to contact native tissue in a body channel; and 
 a collapsible and re-expandable valve structure positioned within an interior portion of the stent and sutured to the stent, the valve structure having three flaps formed entirely of biological tissue, the three flaps positioned between the top and bottom ends of the stent, the valve structure having three commissural points sutured to the stent, the valve structure configured to allow blood to flow in one direction such that blood enters through a bottom opening at the bottom end of the stent and exits through a top opening at the top end of the stent; 
 wherein the valve prosthesis is radially collapsible to an outer diameter of less than 10 mm for introduction by way of a catheter through an inlet opening into the body channel and wherein the outer diameter of the stent is radially re-expandable to a re-expanded dimension sized to engage the native tissue in the body channel with a pressure sufficient for preventing detachment from the body channel and for fixing the valve prosthesis in the body channel without suturing the valve prosthesis to native tissue and wherein the valve prosthesis is detachable from the catheter such that the catheter can be removed from the patient's body and the inlet opening can be closed while the valve prosthesis remains in the body channel; 
 wherein the re-expanded dimension has a diameter of about 30 mm. 
 
     
     
       32. A valve prosthesis for replacing the function of a natural heart valve, comprising:
 a radially compressible and re-expandable stent, the stent being compressible from an expanded condition to a compressed condition having an outer diameter suitable for introduction through a small inlet opening into a body channel by way of a delivery catheter and the stent being re-expandable to a re-expanded condition, the stent having a metallic outer surface for contacting surrounding tissue in the body channel, wherein an outer diameter of the stent in the re-expanded condition is at least 2.7 times larger than the outer diameter of the stent in the compressed condition; and 
 a collapsible and re-expandable valve structure mounted to the stent for folding and expanding together with the stent, the valve structure having three commissural points coupled to the stent, the valve structure having three flaps formed entirely of biological tissue, the valve structure positioned within an interior portion of the stent for preventing blood flow in one direction; 
 wherein the valve prosthesis is detachable from the delivery catheter after deployment in the body channel such that the delivery catheter can be removed from the body channel and the small inlet opening can be closed and wherein the stent has a stiffness in the expanded condition, the stiffness being sufficient to maintain pressure along surrounding tissue in the body channel for securing the valve prosthesis and preventing detachment from the body channel, thereby allowing the valve prosthesis to be permanently implanted in the body channel by way of catheterization without requiring surgical intervention. 
 
     
     
       33. The valve prosthesis according to  claim 32 , wherein:
 the stent is balloon expandable. 
 
     
     
       34. The valve prosthesis according to  claim 32 , wherein:
 the stent is formed of a metallic self-expandable material. 
 
     
     
       35. The valve prosthesis according to  claim 34 , wherein:
 the self-expandable stent has a height comprising a first range configured for fixation in the ascending aorta downstream of the coronary ostia and a second range configured to position the valve structure substantially between the coronary ostia and the left ventricle after implantation. 
 
     
     
       36. The valve prosthesis of  claim 32 , wherein:
 the valve structure is formed entirely of biological tissue from a slaughtered pig. 
 
     
     
       37. The valve prosthesis of  claim 32 , wherein:
 the valve prosthesis is configured to be implanted in the body channel without opening the thoracic cavity. 
 
     
     
       38. A valve prosthesis configured for implantation without surgical intervention for replacing the function of a defective natural valve in an adult human heart, comprising:
 a compressible and re-expandable stent having an inlet end, an outlet end and a metallic outer surface, the stent being radially compressible from an expanded state to a compressed state for introduction through an inlet opening into a body channel by way of a catheter, the stent being re-expandable to a re-expanded state such that the metallic outer surface engages surrounding tissue in the body channel, wherein an outer diameter of the stent in the re-expanded state is at least 2.7 times larger than an outer diameter of the stent in the compressed state; and 
 a collapsible and re-expandable valve structure mounted within an interior portion of the stent between the inlet and outlet ends of the stent for folding and expanding together with the stent and configured for preventing blood flow in one direction, the valve structure having movable flaps positioned between the inlet and outlet ends of the stent for allowing blood to flow only from the inlet end toward the outlet end of the stent; 
 wherein stent stiffness provides the sole means of fixation to surrounding tissue for securing the valve prosthesis to the body channel and wherein the valve prosthesis is detachable from the catheter such that the catheter can be removed from the body channel after deploying the valve prosthesis in the body channel and the inlet opening can be closed such that the valve prosthesis is permanently implantable in the body channel for replacing the function of a native valve without suturing the valve prosthesis to surrounding native tissue. 
 
     
     
       39. The valve prosthesis of  claim 38 , wherein:
 the stent comprises a grate-shaped structure. 
 
     
     
       40. The valve prosthesis of  claim 39 , wherein:
 the stent is self expandable. 
 
     
     
       41. The valve prosthesis of  claim 40 , wherein:
 the stent further comprises an outlet end portion configured for fixation in the ascending aorta at a location downstream of the coronary ostia and an inlet end portion configured for positioning the valve structure substantially between the coronary ostia and the left ventricle. 
 
     
     
       42. The valve prosthesis of  claim 41 , wherein:
 at least the inlet end portion of the stent is substantially cylindrical. 
 
     
     
       43. The valve prosthesis of  claim 38 , wherein:
 the valve structure is formed of biological tissue before the valve prosthesis is introduced through the inlet opening into the body channel. 
 
     
     
       44. The valve prosthesis of  claim 43 , wherein the biological tissue forms two or more adjacent flaps, the flaps forming commissural points between adjacent flaps. 
     
     
       45. The valve prosthesis of  claim 38 , wherein:
 the outer diameter of the stent in the re-expanded state is at least three times larger than the outer diameter of the stent in the compressed state. 
 
     
     
       46. A valve prosthesis configured for implantation in an adult human being without requiring surgical intervention for replacing the function of a defective natural aortic valve, comprising:
 a self expandable metallic stent having an inlet end, an outlet end and a metallic outer surface, the stent being radially compressible to a compressed condition having an outer diameter suitable for insertion into a protection cap and sized for introduction through an inlet opening into a body channel by way of a catheter, the stent configured to self-expand to an expanded condition upon ejection from the protection cap, the stent comprising an outer diameter in the expanded condition at least three times greater than the outer diameter in the compressed condition, the outer diameter being greater than an inner diameter of an ascending aorta such that at least a portion of the metallic outer surface of the stent engages an inner wall of the ascending aorta for counteracting detachment of the valve prosthesis; 
 a collapsible and expandable elastical valve comprising three flaps formed of biological tissue, the elastical valve positioned within an interior portion of the stent for folding and expanding together with the stent, the elastical valve located between the inlet and outlet ends of the stent, the elastical valve having three commissural points sutured to the self expandable stent, the elastical valve configured to allow blood to flow in one direction such that blood is capable of flowing through the stent from the inlet end toward the outlet end; 
 wherein the valve prosthesis is detachable from the catheter such that the catheter can be removed from the body channel after implanting the valve prosthesis and the inlet opening can be closed such that the valve prosthesis is permanently implantable for replacing the function of the defective natural aortic valve without suturing the valve prosthesis to surrounding native tissue. 
 
     
     
       47. The valve prosthesis according to  claim 46 , wherein:
 the self-expandable stent comprises an inlet end portion configured to position the elastical valve substantially between the coronary ostia and the left ventricle. 
 
     
     
       48. The valve prosthesis according to  claim 46 , wherein:
 the outer diameter of the stent in the compressed condition is 10 mm or less. 
 
     
     
       49. The valve prosthesis according to  claim 48 , wherein:
 the outer diameter of the stent in the expanded condition is 30 mm or greater.